Mollusks from the Pepper Shale Member of the Woodbine Formation Mclennan County, Texas

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Mollusks From the Pepper Shale Member of the Woodbine Formation McLennan County, Texas

GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-E Mollusks From the Pepper Shale Member of the Woodbine Formation McLennan County, Texas

By LLOYD WILLIAM STEPHENSON

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 57-68

GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-E

Descriptions and illustrations of new species offossils of Cenomanian age

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1953 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary

GEOLOGICAL SURVEY W. E. Wrather, Director

For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 25 cents (paper cover) CONTENTS

Page Abstract______57 Historical sketch__-___-_-__--__--_l______-__-_-__---__--_-______57 Type section of the Pepper shale member.______58 Section of Pepper shale at Haunted Hill.______-____-__-___---_------58 Systematic descriptions.______..______-_-__-_-_-____---__-_-_-_----_ 59 Pelecypoda______59 Gastropoda.______-____-_-______--_____-___--__-___--__-______64 Cephalopoda-______-______-___--__---_---_-__-— 65 References...... ______65 Index.______67

ILLUSTRATIONS

Plate 13. Molluscan fossils, mainly from the Pepper shale______Following index in

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MOLLUSKS FROM THE PEPPER SHALE MEMBER OF THE WOODBINE FORMATION, McLENNAN COUNTY, TEXAS

By LLOYD WILLIAM STEPHENSON

ABSTRACT My attention was first called to this unit by Mr. R. L. This paper records an assemblage of molluscan fossils from Cannon, in 1926 (oral communication). He informed the Pepper shale member of the Woodbine formation at a me that he had traced a Woodbine-like clay or shale locality known as Haunted Hill, 3.5 miles northwest of Moody, from Hill County, where it was generally recognized McLennan County, Texas. The assemblage includes the follow as belonging to the Woodbine formation, southward ing four species previously described by me from the Woodbine formation: Anomia ponticulanaf, Fulpia pinguis, Cyprimeria through McLennan, Bell, and Williamson Counties, to patella, and "Corbula," hillensis. One species common to the the vicinity of Austin in Travis County. Acting CTL Lewisville member of the Woodbine, previously described as this information I visited localities in Hill, McLennan, Eoioffyra sp., is here given the new specific name, Exogyra aquil- and Bell Counties in 1926, and was able to confirm tH lana. The following six additional new species are described: presence of the Woodbine-like shale unit between tl ^ Breviarca (Sanoarca) spiritalis, Brevlarea (Sanoarca) calciana, Gyclorisma nodana, Sinonia lozoi, Parmicorbula moodiana, and Buda limestone below and the undoubted Eagle Ford Aiwhura umbrana. One new variety, Turritalla shitleri pep- shale and interbedded flaggy limestone above. I did perana, is described. The genus Baculites, not previously not at the time have an opportunity to restudy tl ^ recorded from the Woodbine formation, is represented by a section in Travis County. However, on a visit in 1928 fragment of a small smooth unidentified species. I noted several feet of dark noncalcareous Woodbind- The evidence afforded by this assemblage confirms the con like clay forming the base of the section (mainly Eagle clusion that the Pepper shale member is the southward ex Ford) which intervenes between the Buda limestone tension of the Woodbine formation, and is probably the exten sion of the Lewisville member of that formation. below and the Austin chalk above on Bouldin Creek south of Colorado River at Austin. (Stephenson, HISTORICAL SKETCH 1927, pp. 3, 4.) In the Guide Book of the 1951 Field Trip of the East Texas Geological Society (Cretaceous The stratigraphic unit from which the fossils de of Waco, Texas Area, p. 155), the thickness of this clay, scribed in this paper were obtained was named the designated Pepper, is given by Adkins and Lozo as 34 Pepper formation by W. S. Adkins in 1933 (Univ. of feet. Texas Bull., 3232, pp. 239, 270, 417-422). This shale The shale composing this unit is only meagerly fo- unit lies between the top of the Comanche series and siliferous and the few macrofossils heretofore found in the flaggy limestones and dark shales that form the base it are poorly preserved. Adkins listed several genera of the Eagle Ford shale (Gulf series) of Late Cre of pelecypods, gastropods and ammonites, preserved as taceous age. It crops out in a narrow belt extending delicate impressions, from the type locality of the unit, from McLennan County, Texas, southward through Bell but he did not consider them diagnostic of exact age and Williamson Counties to Travis County. The unit (1933, p. 419). had been known to earlier geologists, some of whom The late Helen Jeanne Plummer (in Adkins, 1933, considered it a southward extending s^ale f acies of the pp. 419, 420) identified arenaceous Foraminifera from Woodbine formation, and others a basal member of the the lower part of the type section of the Pepper shale, Eagle Ford shale. The thickness of the unit in central belonging to the genera Ammobacuities, Ammodiscus, McLennan County is 75 feet or less, from which area and Reaphax. She says, southward it gradually becomes thinner and finally These species have no relation to those of the Grayson or Del Bio formations, but are similar to species in the Eagle Ford and pinches out by overlap in Travis County south of other Upper Cretaceous faunal groups. I feel no hesitancy in Austin. referring this shale to the Upper Cretaceous series. 57 58 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 In 1946 Alfred R. Loeblich, Jr., described eleven new spotty, but at levels fossils occur, as shale ammonites at Alli species of arenaceous Foraminifera from the type lo gator Creek; in fossiliferous limy seams at Haunted Hill. cality of the Pepper shale on Bird Creek, a small tribu TYPE SECTION OF THE PEPPER SHALE MEMBER tary of Leon River, 4 miles east-northeast of Belton, The type section of the Pepper shale member of the Bell County, about 500 feet southeast of the Belton- Woodbine formation is in small northwest-facing bluffs Temple highway (U. S. 81). Loeblich says (pp. 132- of Bird Creek, a small tributary of Leon River, 500 feet 133): southeast of the Belton-Temple highway (U. S. 81), Environment.—The writer believes these sediments were de about 4 miles east-northeast of Belton, Bell County. posited in shallow waters of low salinity, because of the The member was named from nearby Pepper Creek. presence of abundant siderite and limonite concretions, the presence of large numbers of reworked calcareous forms, the The following description of the type section is adapted absence of any indigenous calcareous Foraminifera in the type from the description of the measured type section given Pepper, the small size of the arenaceous species, the large amount by Adkins and Lozo (p. 130). of organic matter in some of the samples, and the limited mega- fauna, which consists only of mollusks and worms. Section on Bird Creek, 4 miles east-northeast of Belton, Correlation.—The present fauna consists entirely of new Bell County, Teaeas species, and hence cannot settle the question of the correlation Gulf series: Feet of the Pepper formation, but perhaps can be used for com Eagle Ford shale: parison when the microfauna of the Woodbine is better known. Limestone, wavy-bedded, yellowish-brown, massive to platy and thin-bedded, witl a At the time Loeblich's paper was published he knew thin bed of bentonite near the middle; of the presence of this assemblage of arenaceous Forami locally with ammonites and other n^ol- nifera only at the type locality of the Pepper shale, but lusks, in part fragmentary—————————— 2 + Shale, black, fissile, slightly calcareous, with he informs me that at a later time he found the same abundant globigerinids and other shells—— 1. 5 assemblage in the few feet of dark noncalcareous shale Unconformity immediately overlying the Buda limestone in the Woodbine formation (Pepper shale member) : Bouldin Creek section south of Austin. Shale, purplish-black, noncaicareous, with sele- In recent years the age and stratigraphic relation nite crystals, and with yellow jarosite crys tals, films and streaks in weathered psrts ships of the Pepper shale have been more critically of the shale; contains arenaceous f oraminif- studied in the Waco area (including parts of Bell, Mc ers and thin nacreous shells and impres Lennan and Hill Counties) by Adkins and Frank E. sions of mollusks______—————_—_ 22 5 Lozo, and the results of their field and laboratory studies Shale, gypsiferous, with many euhedral sele- are recorded in a paper published as part of "A Sym nite crystals______———————————— 0.6 Clay, sandy, carbonaceous, gypsiferous, with posium for the 1951 Field Trip Sponsored by the East quartz and phosphate pebbles, fish remains, Texas Geological Society" (1951, pp. 101-161). It was lignitized wood and reworked Del Bio [fie] my privilege to participate in this field trip, which was fossils______-____ 0. 45 held May 3 to 5, 1951. The fossils described in the Unconformity Comanche series: present paper (U. S. G. S. Coll. 23634) were collected Grayson marl (formerly Del Rio clay) : by me during the course of the trip at the locality des Clay, gray, massive, calcareous, fossiliferou«_ 1. 5 ignated "Haunted Hill" by Adkins and Lozo (pp. 134, Limestone, gray, soft, gritty, clayey————„_ 0. 3 185). Clay or marl, exposed downstream——————— 25 +

As a result of their study of the Pepper shale Adkins Total + and Lozo interpreted this unit to be a southward ex SECTION OF THE PEPPER SHALE MEMBER AT tending shale facies of the Lewisville member of the HAUNTED HILL Woodbine formation. They summarize their conclu sions in the following words (1951, p. 116) : Haunted Hill is a low hill at the south end of a series of low hills, known as Moody Hills, about 3.5 miles In the area north of the Brazos, strata of porous and crumbly northwest of Moody, McLennan County. T1 °. Pepper to friable, locally indurated, ferruginous sandstones occur, al ternating with Pepper-type black, noncalcareous shales. South shale is well exposed in a bare area on the upper slope ward these sandstones thin and disappear laterally within the of Haunted Hill; neither the base nor the top of the body of the shale formation, which is composed thereafter en member are seen in the exposure. The description of tirely of Pepper facies. This is a noncalcareous, nonearbonace- the shale given below is essentially a copy of that given ous (except for ferrous carbonate and thin shells), black, locally by Adkins and Lozo, who measured in detail the beds glistening shale which contains pyrite and on the outcrop devel ops gypsum, celestite, siderite, jarosite, and other minerals. The exposed in the slope of the hill. They treated the shale outcrop is poor in soil and vegetation. The fossil zonation is as a formation of the Woodbine group. MOLLUSKS FROM THE PEPPER SHALE, WOODBINE, OF TEXAS

Incomplete section of Pepper shale exposed in the upper slope The molluscan fauna from the Pepper shale at tin of Haunted Hill, 3.5 miles northwest of Moody, McLennan Haunted Hill locality, as listed above, seems to afford County, Texas clear confirmatory evidence of the Woodbine age of tin Woodbine formation (Pepper shale member) : Feet shale. The four previously described species, marked Shale, bluish-black, lustrous, jarositic and selenitic_ 10.0 with an asterisk (*), are all recorded from the "Wood Siderite concretions, small, reddish-brown, flat, oval_ 0.1 Shale, bluish-black, lustrous, jarositic and selenitic_ 4. 0 bine, and all the genera to which the new species (ard Siderite concretions__—______0. 2 one variety) are assigned are common to that formation. Shale, bluish-black______3. 5 Of these, Breviarca (Sanoarca) and Sinonia seem es Limestone shell breccia or coquina, finely sandy, pecially significant as they are known only from tin gray, weathering yellowish, abundantly fossilifer- Woodbine. The new species, Exogyra aquillana, previ ous, mainly in the form of shell fragments, but in cluding a few shells with features partly or nearly ously described as Easogyra sp., and "CorbulaP hillensis completely preserved; the fossils described in this (Stephenson), are recorded from the Lewisville mem paper were obtained from this bed______—__ 0. 2 ber of the Woodbine, in southern Hill County in beds Shale, bluish-black______1.0 that are considered by Adkins and Lozo to be Woodbine Siderite concretions, platy, dark reddish-brown___ 0.1 representatives of the Pepper shale. Two previously Shale, bluish-black ______2.0 Sideritic layer______0.1 described species, Anotnia, ponticulana, and Fulpia Shale, bluish-black ______3.1 pinguis, range throughout the Woodbine. The am monite genus Baculites Lamarck has not heretofore been Total ______24.3 recorded from the Woodbine. The only previously de Adkins and Lozo estimate that the base of the pre scribed species in the list, restricted to the Lewisville ceding section as exposed lies about 5 feet above the member of the Woodbine is "Corbula" hillensis (Ste contact of the Pepper shale with the underlying Gray- phenson) , but the list affords no evidence opposed to tin son marl (formerly Del Rio clay), and that about 10 Lewisville age of the Pepper units. feet of Pepper shale has been eroded from above the The new forms here described constitute additions exposed section; this would indicate that the total to the fauna of the Woodbine formation recorded in thickness of the member in this area is approximately my recent monograph (U. S. Geol. Survey Prof. Pap^r 40 feet. 242), and the present paper may be considered a sup The fossils here described were obtained by careful plement to it. preparation from pieces of the coquina limestone hast ily collected during a short stop of the field party at SYSTEMATIC DESCRIPTIONS Haunted Hill. It may be assumed that the possibilities Class PELECYPODA of the fauna obtainable from this source were by no Order PRIONODESMACEA means exhausted. The following genera and species were identified from the coquina bed: Family ARCIDAE Genus BREVIARCA Conrad, 1872 Molluscan fossils identified from coquina limestone in Pepper shale at Haunted Hill, McLennan County, Texas Subgenus SANOARCA Stephenson, 1953 ^Indicates previously described Woodbine species] Breviarca (Sanoarca) spiritalis Stephenson, n. sp. Pelecypoda: Breviarca (Sanoarca) spiritalis, n. sp. Plat 13, figures 1, 2 B. (S.) calciana, n. sp. Shell small, subtrapezoidal in outline, strongly in Ostrea sp. flated centrally, inequilaterial, subequivalve. Umbonal Exogyra aquillana, n. sp. *Anomia ponticulana Stephenson? ridge distinct, subangular, a little rounded at the angle. *Fulpia pinauis Stephenson Posterodorsal slope steeply descending, broadly exca *Cyprimeria patella, Stephenson vated. Beaks prominent, strongly incurved, slightly Cyclorisma nodana, n. sp. opisthogyrate, situated slightly in advance of the mid- Sinonia lozoi, n. sp. length. Anterior margin forming an obtuse subangle *"Corl)ula" hillensis (Stephenson) Parmicorfiula? moodiana, n. sp. with the forward end of the area, regularly rounded Gastropoda: below; ventral margin broadly rounded; posterior Turritella shuleri pepperana, n. var. margin obtusely subangular below at end of umbonal Anchura umbrana, n. sp. ridge, nearly straight to slightly convex and inclined Cephalopoda: forward above, meeting the hinge line at an obtuse Baculites sp. (cf. B. gracilis Shumard) Ammonoid fragment (may be Acanthoceras Neumayr or angle. Surface bears raised concentric lines that be Metoicoceras Hyatt) come stronger near the margins, and obscure radiating 60 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 lirae that also become a little stronger near the margins, ligamental grooves. Hinge long, narrow, straight on especially on the dorsal slopes. upper edge, widening slightly and arching down a Dimensions of the holotype, a right valve: Length little at the ends; teeth numerous, central or^s trans 9.1 mm, height 6.4 mm, convexity about 3 mm. verse, those on the wider ends slightly oblique. Area long, subtriangular, straight on lower edge, ap This species resembles Breviarca (Sanoarea) spirit- parently smooth; because ligamental cross striations alis in size but is more elongated, more sharply pointed seem to jbe absent, the species is referred to the subgenus at the posterior end, has a coarser development of con Sanoarca Stephenson. Hinge long, narrow, straight on centric growth ridges toward the margins, and has upper edge, widening a little and arching down slightly practically no radial sculpture. toward each end; teeth numerous, not sharply pre Types.—Holotype, a left valve, U.S.N.M. 108338; 1 served, transverse centrally, becoming slightly oblique figured paratype, U.S.N.M. 108339; 10 unfigured para- toward the ends of the hinge. Inner surface not un types, U.S.N.M. 108340. covered. Brdviarca (Sanoarea) faucatia Stephenson, is of Super family OSTRACEA comparable size, but the present species is longer in Family OSTREIDAE proportion to height, and has a much longer, straighter and more delicate hinge. Breviarca ($.) faucana is re Genus OSTREA linne, 1758 corded from the Euless and Lewisville members of the Ostrea sp. Woodbine formation. The abundant B. ($.) hdbita Two small water-worn specimens of Ostrea Linne are Stephenson resembles B. (S.} spiritalis in shape but present in the collection from Haunted Hill. One of is smaller and has sharper concentric and radiating them is subcircular in outline, relatively thick and lirae. Breviarca (S.) calciana, n. sp., is more elon measures 10 mm in length. The other is subovate in gated, more sharply pointed posteriorly, has a stronger outline, shows the hinge rather obscurely, and is 13 mm development of concentric growth ridges, and more long and 15 mm high. These may be young examples obscure radiating lines. of Ostrea soleniscus Meek, a common species in the Types—Holotype, U.S.N.M. 108336; 15 imfigured Woodbine formation. U.S.N.M. 108341. paratypes, U.S.N.M. 108337; all from the Pepper shale member of the Woodbine formation, at the Haunted Genus EXOGYRA Say, 1820 Hill locality. Exogyra aquillana Stephenson, n. sp. Breviarca (Sanoarca) calciana Stephenson, n. sp. Plate 13, figures 5-8 Plate 13, figures 3, 4 Exogyra sp. Stephenson, U. S. Geol. Survey Prof. Paper 242j p. 78, pi. 18, figs. 4-6, 1953. Shell small, elongate-subtrapezoidal in outline, in flated, inequilateral, subequivalve, broad in umbonal This species was described and figured without a region; umbonal ridge long, subangular, concave up specific name, as indicated above. The shells, which ward in trend; posterodorsal slope long, descending, are present in great numbers at the Aquilla Creek lo broadly excavated, deepest near and parallel to the cality, were thought to be a depauperate assemblage of umbonal ridge; beaks moderately prominent, incurved, some larger species. Four shells found at the. Haunted slightly opisthogyrate, situated about two-fifths the Hill locality seem to be conspecific with th*. Aquilla length from the anterior end; anterior margin regu Creek shells, and to indicate that the species has a larly rounded, ventral margin very broadly rounded, rather wide geographic range, and is of value as an posterior extremity rather sharply subangular at end of index fossil. .It seems desirable therefore for con umbonal ridge, posterior margin nearly straight to venience of reference to give it a specific name. The slightly convex, inclined strongly forward, meeting the available material includes only left valves. One hinge line at a wide obtuse angle. Surface smooth in internal mold of a small Exogyra in a matrix of fer the umbonal region, but away from the beak the growth ruginous sandstone of the Euless member of the Wood lines increase in coarseness and toward the margins bine formation on State Highway 183, withir 1.2 miles form round-crested growth ridges spaced about four to west-southwest of Euless, Tarrant County, Texas the millimeter radially. (U.S.N.M. 105227), probably belongs to this species. Dimensions of the holotype, a left valve: Length 11.6 This specimen was described, but not figured, on page 78 mm, height 7.3 mm, convexity 3.5 mm. of Professional Paper 242. Area greatly elongated, subtriangular, apparently The largest specimen (a paratype) measures about smooth, showing neither transverse nor chevron-shaped 23 mm in its greatest dimension (height). Most of the MOLLTJSKS FROM THE PEPPER SHALE, WOODBINE, OF TEXAS 61 shells are less than 17 mm in height. The shells are Order TELEODESMACEA smooth, strongly convex, and narrow in the umbonal Superfamily CYRENACEA region. The beak is sharply twisted at the tip except Family CYRENIDAE as it may be modified by the scar of attachment. The shells show individual variations in form. The speci Genus FTJLPIA Stephenson, 1946 mens consist of internal molds to which some shell sub Fulpia pinguis Stephenson stances adheres. Fulpia pinguis Stephenson, Jour. Paleontology, vol. 20, No. 1, Dimensions of the holotype: Length 11 mm, height 15 p. 68, figs. 1-4, 1946. mm, convexity 6 mm. Fulpia pinguis Stephenson, U. S. Geol. Survey Prof. Paper 242, p. 97, pi. 23, figs. 1-4, 1953. The adductor scar as seen impressed on the internal mold of one paratype is of moderate size, subcircular, Fulpia pinguis Stephenson is represented in the situated a little below midheight and a little back of Haunted Hill collection by 5 poorly preserved bat midlength. identifiable specimens. The shape, surface features, and Types.—Holotype, U.S.N.M. 105225a; 1 figured para- characters of the partly preserved right and left hinges agree well with the types from the Lewisville member type, U.S.N.M. 105225b; 53 unfigured paratypes, of the Woodbine formation 011 Sheep Creek in Fanrin U.S.N.M. 105226; all from Aquilla Creek at base of County, Texas. The largest specimen from Haunted Lewisville member of Woodbine formation, 1.2 miles Hill, a left valve, measures: Length about 24 mm, east of Aquilla, Hill County, Texas (U.S.G.S. Coll. height about 21.5 mm, convexity about 9.5 mm. The 19018). One figured paratype, U.S.N.M. 108342; 3 species ranges throughout the full thickness of the unfigured paratypes, U.S.N.M. 108343; from the Pep Woodbine formation. U.S.N.M. 108345. per shale member of the Woodbine formation, 11 feet above base, at Haunted Hill, on the Paul Alexander Superfamily VENERACEA farm, about 3% miles northwest of Moody, McLennan Family VENERIDAE County, Texas (U.S.G.S. Coll. 23634). One unfigured Genus CYPRIMERIA Conrad, 1864 paratype, U.S.N.M. 105227; from Euless member of Woodbine formation on State Highway 183, within 1.2 Cyprimeria patella Stephenson miles west-southwest of Euless, Tarrant County, Texas Cyprimeria patella Stephenson, U. S. Geol. Survey Prof. Paper (U.S.G.S. Coll. 19040). 242, p. 108, pi. 27, figs. 12-18,1953. The collection from Haunted Hill includes 11 poorly Superf amily ANOMIACEA preserved, and in part incomplete, specimens of Cypn- Family ANOMIIDAE meria patella Stephenson, 4 right valves, 6 left valves, and one small shell with both valves intact. These Genus ANOMIA (Linne, 1758) Miiller, 1776 specimens range from 8.5 mm to about 40 mm in length. Anomia ponticulana Stephenson? The holotype, a shell 52 mm long is from the Templeton Anomia ponticulana Stephenson, U. S. Geol. Survey Prof. Paper member of the Woodbine formation near old Slr.te 242, p. 81, pi. 20, figs. 1-4,1953. Shoals on Red River, 8 miles east of Arthur City, Lam ar The Haunted Hill locality yielded six small poorly County, Texas. The shells from Haunted Hill do rot preserved specimens of Anonua that probably belong differ from the types in any essential feature. The to A. ponticulana Stephenson. The typical fine radiat species is not recorded from the Lewisville member of ing lirae of that species are wanting, but the outer shell the Woodbine formation, with which the Pepper shale layer of the specimens appears to have been worn or has been correlated. U.S.N.M. 108346. peeled off before preservation. Besides, even on the Genus CYCLORISMA Ball, 1902 typical shells, the radiating lirae are usually obscure or Cyclorisma nodana Stephenson, n. sp. wanting and the largest of these six specimens is only 12 mm in length. They show some variations in form, Plate 13, figures 9-12 but all are subcircular left valves of low convexity. This is a common species at Haunted Hill, though, U.S.N.M. 108344. as is usually true of fossil shells in coquina, most of the

231314—53- 62 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 specimens are poorly preserved. Several of them are Types.—Holotype, U.S.N.M. 108347; 2 figur-d para- in fair condition. types, XJ.S.N.M. 108348; 20 unfigured paratypes, Shell small, thin, subcircular in outline, slightly in U.S.N.M. 108349. equilateral, equivalve, moderately convex, greatest in Genus SIHOMTA Stephenson, 1953 flation above the midheight. Beaks rather prominent, incurved, prosogyrate, approximate, situated a little in Sinonia lozoi Stephenson, n. sp. advance of the midlength. Lunule not excavated but Plate 13, figures 13-15 distinctly outlined by a narrow groove; escutcheon This species is represented in the collection by one wanting. Surface with numerous, regularly spaced, apparently adult left valve whose margin ie broken round crested, concentric ribs, numbering 4 to the mil away in places, and by four fragments of young in limeter in the radial direction on the adult stage. dividuals, two left and two right valves, all with beaks Dimensions of the holotype, a left valve: Length 13 preserved; the large left valve (holotype) is complete mm, height 12.5 mm, convexity 5 mm. The largest enough to show outline, form, surface features, and specimen in the collection is about 15 mm long. hinge. One fragment, a right valve, shows a nearly Ligament external, about 4.5 mm long in the holo complete, partly worn hinge. type; ligamental groove sharply incised, nymph nar Shell of medium size, subovate-elongate in outline, row, plain. Hinge with three cardinal teeth in each thin, compressed, strongly "inequilateral, equivalve. valve; lower margin of hinge sinuous, convex inward Beaks moderately prominent, incurved, prosogyrate, below the beak, concave outward back of the beak; situated about one-third the length of the sh°>ll from laterals wanting. The cardinal teeth are not very the anterior end. Lunule and escutcheon wanting. sharply preserved in available material. In the right Anterodorsal margin steeply descending, broadly valve the anterior cardinal tooth is small, short, oblique arched; anterior margin rounded less than a semicircle; forward; middle tooth nearly direct inward, apparently ventral margin very broadly rounded; posterio^ margin thick, probably covered with secondary calcite; poste less sharply rounded than the anterior margin, fullest rior tooth oblique rearward, long, subtrigonal, prob below, slightly subtruncate in the adult; posterodorsal margin long, broadly arched, gently descending. Sur ably bifid; anterior and middle teeth separated by a face showing only unequally developed incremental narrow, deep socket, and middle and posterior teeth by lines and low, narrow, irregular ridges. a long oblique trigonal socket of moderate depth. In Dimensions of the holotype: Length 32.5 mm, height the left valve the anterior and middle cardinal teeth about 23 mm, convexity about 6.5 mm. unite at the top to form an inverted V the limbs of Ligament external, opisthodetic, groove narrow, which are separated by a trigonal socket; the posterior deeply impressed, nymphs long, narrow, and rather tooth is long, narrow, and very oblique and is separated prominent. Three cardinal teeth in left va^ve; anterior from the middle tooth by a long, wide, oblique, trigonal and median cardinals about equal in size and joined at socket. The pallia! line is well back from the margin upper ends to form an inverted V inclosing a deep and the pallia! sinus, as obscurely seen on the internal trigonal socket; anterior cardinal strong, slightly bifid, mold of one of the paratypes, is V-shaped, moderately directed inward and slightly forward; middle tooth deep, and points toward the beak. simple, directed inward and slightly backward; poste In form and in hinge characters this species is very rior tooth long, strongly oblique rearward pr.ralleling much like the genotype, Cyclorisma carolinensis (Con the nymph, weak, separated from the middle cardinal rad), from the Snow Hill marl member of the Black by a long, wide, and deep trigonal socket; in front of Creek formation at Snow Hill, North Carolina, but the anterior cardinal is a moderately deep trigonal socket opening into a shallow lateral channel that ex the individuals average one-third or less in size. tends forward about 5 mm. Features of the inner sur This species resembles Cyclorisma orbiculata Ste- face not uncovered. The hinge of the right valve is phenson from the Templeton member of the Woodbine nearly complete in a shell fragment that shows some formation in Lamar County, Texas, and is about the what worn nymph and teeth. The anterior cardinal same size, but it is proportionately a little longer; tooth is of medium strength and is separated from a the concentric surface ridges are stronger and more strong trigonal middle tooth by a narrow deep socket; regular, and a lunule is present, outlined by a distinctly the posterior cardinal tooth is long, narrow, bifid, impressed line. Specimens that have the hinge covered strongly oblique; it is separated from the middle tooth or missing might easily be mistaken for a representa by a long, narrow, trigonal, oblique socket ?,nd from tive of the genus Fulpia Stephenson. the nymph by a long, narrow socket. MOLLUSKS FROM THE PEPPER SHALE, WOODBINE, OF TEXAS 63 Although the holotype of this species is about the of the posterodorsal slope. Surface of left valve nearly size of the holotype of Sinonia levis Stephenson (the smooth, or with weakly and irregularly developed con type species of the genus, from the Woodbine forma centric ribs. tion), the former is higher in proportion to the length, Dimensions of the plesiotype (right valve) shown in has a heavier hinge plate, a slightly longer ligament, plate 13, figure 20: Length 13.1 mm, height 9 mm, con and a somewhat more prominent umbonal region. vexity 4.5 mm. Types.—Holotype, U.S.N.M. 108350; 1 figured para- Hinge of right valve with one cardinal tooth of type, U.S.N.M. 108351; 3 unfigured paratypes, U.S. medium size below the beak; back of the tooth is a deep N.M. 108352. Named in honor of Frank E. Lozo. resiliary pit; in one plesiotype the tooth appears to be somewhat worn. Hinge of left valve has a rather Superfamily MYACEA short, somewhat worn resiliary platform which is di Family CORBU1IDAE rected obliquely rearward and slopes steeply forward toward a deep trigonal cardinal socket. Internal molds Genus CORBULA Lamarck, 1799 show that the anterior adductor scar is small and sub- "Corbula" hillensis (Stephenson) ovate, and the posterior adductor small, elongate, and Plate 13, figures 16-20 seated on a raised platform. Parmicorbula? liillensis Stephenson, U. S. Geol. Survey Prof. Types.—Holotype, U.S.N.M. 105555; paratypes, Paper 242, p. 133, pi. 33, figs. 13-15,1953. U.S.N.M. 105556 (figured) and 105557. Plesiotypes from the Haunted Hill locality (U.S.G.S. Coll. 23634; The holotype and paratypes of this species are in U.S.N.M. 108353a-c); numerous unfigured examples ternal and external molds in fine ferruginous sandstone from Haunted Hill, U.S.N.M. 108354. from a roadside exposure 3 miles northeast of Whitney, Occurrence.—Holotype and paratypes, northeast- Hill County, Texas; the collection was made by Roy T. southwest road, 3 miles northeast of Whitney, Hill Hazzard about 1941. The species is represented at the County (U.S.G.S. Coll. 19020). Three plesiotypes and Haunted Hill locality by many shells, mostly worn or numerous other specimens from Haunted Hill, 3^ incomplete, but a few are nearly complete and show miles northwest of Moody, McLennan County the form, surface features, and hinges with only minor (U.S.G.S. Coll. 23634). Eavine east of road to Ghol- defects. Both right and left valves are present, but son, 2.8 miles east of Gholson (U.S.G.S. Coll. 14587), the two valves are not found together as one individual. and Elm Creek, 2 miles southwest of Wiggins, 6.5 miles No features indicating the presence of an accessory southwest of the town of West, McLennan County siphonal plate back of the terminus of the left valve can be detected in any of the shells, for which reason (U.S.G.S. Coll. 23635). the species is here treated as belonging to "Corbula", Genus PARMICORBTTLA Yokes, 1944 as this name is used in a broad sense; it falls definitely within the family Corbulidae. The species is here re- Parmicorbula? moodiana Stephenson, n. sp. described on the basis of the more complete specimens Plate 13, figures 21-23 now available. Shell small, subtrigonal in outline, strongly inflated Shell of medium size, subtrigonal in outline, strongly in the umbonal area, narrowing and becoming strongly inflated in the umbonal and anterior parts, narrow and constricted posteriorly, inequilateral, inequivalve. The strongly constricted in the posterior part, inequilateral, posterodorsal slope forms a broadly excavated band inequivalve. Beaks very prominent, incurved, proso- crossed only by growth lines, bounded by a subangular gyrate, situated a little in advance of the midlength on umbonal ridge, and extending radially to the truncated the right valve, nearly central on the left valve; right terminus. Beaks very prominent, incurved, proso- valve more strongly inflated than the left and beak more gyrate, situated at or a little anterior of the midlengMi. strongly incurved. Anterodorsal margin steeply de Anterodorsal and anterior margin rather sharp!y scending, broadly arched; anterior margin sharply rounded below the midheight; ventral margin broac'ly rounded below the midheight; ventral margin broadly rounded becoming slightly concave near the posterior rounded. Posterior margin of right valve short, trun extremity; posterior margin short, subtruncated, in cated, inclined forward, meeting the posterodorsal mar clined slightly forward; posterodorsal margin gently gin at an obtuse angle; the latter margin gently inclined, inclined, nearly straight or slightly sinuous. Surface nearly straight or a little upturned at the rear. Pos of right valve covered with pronounced, irregular terior margin of left valve bluntly subangular below concentric ribs that increase in coarseness outward to the midheight, rounding upward into the posterodorsal ward the margins; these ribs end rearward a little short margin. The two valves were not seen together but the SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 narrow, flattish, posterior extension of the right valve, sculpture, but the description is based mainly on the compared with the shorter blunt extremity of the left holotype. valve suggest that there was in the living shell an acces The shell is high-turreted; the sides of the whorls sory siphonal plate at the terminus of the latter; this are nearly flat and are separated by a moderately deep plate would be lost when the two valves became sepa sutural depression. Each whorl bears 4 primary noded rated. The existence of this plate is also suggested by spirals; the uppermost primary is the smallest of the the presence of a radial groove on the outer surface of four and bears the most numerous small, closely spaced the posterior extension of the right valve, possibly re nodes; the second primary below the suture i? largest flecting a radial ridge on the inner side of this extension; and bears the coarsest and most prominent nodes; the on the typical Pannicorbula a ridge of this sort on the two lowest primaries are of about equal strength and inner side of a posterior projection stands opposite a bear nodes of intermediate size and prominence. similar ridge on the inner side of the characteristic Between the second and third primary below the suture accessory plate, the function of the two ridges being to is a rib of medium strength that may be clarsed as a separate the two siphons where they pass out rearward. secondary spiral; it is neatly ornamented witl numer On the right valve the umbonal part of the outer sur ous, small beadlike nodes; between the lowermost face, including one-third to one-half the total surface, primary and the lower suture are two nearly smooth is smooth; the rest of the surface in front of the umbonal spirals of about secondary strength. All the other ridge is covered with small, closely spaced concentric intermediate primaries are very small (tertiaries) and ridges, which increase in coarseness toward the outer are more or less clearly ornamented with very tiny margin, where they number 3 or 4 to the millimeter nodes; they number one to three in the interspaces be in the radial direction. The surface of the left valve tween the primaries and secondaries. The periphery shows only obscure growth ridges interrupted on some is subangular and the flatttish base is covered with fine, shells by an occasional groove marking a resting stage rather obscure spiral lirae. The diameter of the largest in growth. whorl of the holotype is 6 mm. Dimensions of the holotype, a right valve: Length 5 Because of the individual differences in the spiral mm, height 3.6 mm, convexity about 1.5 mm. A larger sculpture of the typical Turritella shuleri the sculpture right valve (a paratype) measures: Length about 5.5 of this variety cannot satisfactorily be compared with mm, height 4 mm, convexity about 2 mm. The left valve it in detail; in general, however, the former possesses is slightly shorter than the right. thicker and stronger primary spirals, and there spirals Hinges and internal features not well enough uncov bear much coarser nodes, especially the two upper ones, ered for description. than is true of the latter at the same stage of growth. The species resembles Parmicorbula cornelians Compared with the typical T. shuleri the base of this Stephenson, but it is smaller, not quite so plump, and variety appears to be flatter, the periphery more angu less coarsely sculptured. lar, and the suture a little more deeply impressed. Types.—Holotype, a right valve, U.S.N.M. 108355; 2 Types.—Holotype U.S.N.M. 108358; 10 unfigured figured paratypes, U.S.N.M. 108356; unfigured para- paratypes, U.S.N.M. 108359. types, 3 left valves and 5 right valves, U.S.N.M. 108357. Family AFORRHAIDAE Class GASTROPODA Genus ANCHURA Conrad, 1860 Order CTENOBRANCHIATA Anchura umbrana Stephenson, n. sp. Family TTTRRITELLIDAE Plate 13, figures 25-30 Genus TTTRRITELLA Lamarck, 1799 Shell rather small f or the genus, high-turre^ed, with Turritella shuleri pepperana Stephenson, n. var. spiral angle of about 30 degrees. Protoconch not pre Plate 13, figure 24 served. Whorls 6 or 7, gently convex on the side, the The coquina limestone in the Pepper shale at Haunted larger whorls ornamented with axial ribs and spiral Hill yielded several fragmentary specimens of a noded lirae; on the penultimate whorl the axials are small, form of Turritella, Lamarck, representing early stages closely crowded, and number at least 22; they are of growth, all poorly or incompletely preserved. They strongly oblique and sinuous in trend, being slightly are closely related to T. shuleri Stephenson from the convex forward below, broadly concave forward above, Lewisville and Templeton members of the Woodbine bending strongly forward just below the suture; the formation and are here treated as a variety of that spirals are small, obscure centrally, and become a little species. The shells show some variation in details of stronger toward the sutures both below and at ove. On MOLLUSKS FROM THE PEPPER SHALE, WOODBINE, OF TEXAS 65 the body whorl the axials extend well down the basal and others as belonging to the genus Sciponoceras slope, becoming weaker toward the lip; they are broadly Hyatt. In this connection attention is called to convex forward in trend except near their upper ends Shumard's statement that his species was found on where they bend forward to the suture. The spirals Shawnee Creek in Grayson County, Texas (1860, p. are obscure on the inflated part of the body whorl but 596). The only creek by this name shown on present become stronger above, the uppermost just below the available maps of Grayson County is northwest of Deni- suture being relatively coarse; about 10 spirals are pre son in a drainage basin that lies entirely within an area sent on the basal slope, the upper 4 or 5 being weak to underlain by strata of the Comanche series. Shumrrd obscure, and the lower 5 or 6 relatively strong; low did not illustrate the species, his type material is p^e- rounded nodes mark the intersections of the axials with sumed to be lost, and an identification can not safely be the stronger spirals. The aperture is ovate-elongate. made from his published description. If the Shawnee The outer lip is expanded and winglike but is poorly Creek on which G. G. Shumard (brother) collected the preserved in the available material. A rather obscure types of Baculites gracilis is the same as the creek c^r- impression on one paratype (pi. 13, fig. 29), and one rently known by that name there is reason to doubt tl at wing broken from its parent shell (pi. 13, fig. 30) indi the species of Sciponoceras associated with Metoicoceras cate the presence of one thick, winglike, upturned pro whiteittyatt in the stratigraphically higher Eagle Ford jection ; the latter figure shows the interior of the broken shale is correctly referable to B acuities gracilis SI u- wing. The inner lip forms a rather broad band of callus mard; it probably needs a new specific name. over the parietal wall. No representatives of Baculites are recorded in my Dimensions of the holotype, an. incomplete shell: recent (1953) treatise on the larger invertebrate fossils Diameter, exclusive of the expanded lip, about 11.5 mm, of the Woodbine formation of Texas. Adkins (1920, height 24+ mm. p. 74) describes a species, Baculites comanchensis, from Types.—Holotype, U.S.N.M. 108360; 4 figured para- the Pawpaw formation (upper part of Comanche types, U.S.N.M. 108361; 30 or more unfigured paratypes, series), near Fort Worth, Texas. This species he later mostly poorly preserved, U.S.N.M. 108362. referred tentatively to Cyrtochilus Meek (1928, p. 207). This is about the lower limit of the known stratigraphic Order CEPHALOPODA range of Baculites (sensu lato). Family LYTOCERATIDAE Family COSMOCERATIDAE? Genus BACULITES Lamarck, 1799 Genus ? Baculites sp. Ammonoid fragment (Acanthoceras? or Metoicoceras?) Plate 13, figure 31 The coquina bed at Haunted Hill yielded one small The genus Baculites Lamarck (sensu lato) is repre scarcely identifiable ammonoid fragment that may be sented in the collection from Haunted Hill by one frag long to the genus Acanthoceras Neumayr, or possibly ment which apparently pertains to a small smooth to Metoicoceras Hyatt. The specimen shows two lateral slender species having a broadly ovate cross section. radiating ribs, each with a fairly high elongated node The specimen is slightly crushed on one side but its on the umbilical shoulder; between these two ribs is dimensions are approximately as follows: Length part of a shorter rib, and part of another short rib 13+mm, greatest dorso-ventral diameter 5.8 mm, great appears to the left of the three ribs. U.S.N.M. 1083*>4. est transverse diameter 5 mm; at the small end the dorso-ventral diameter is about 5 mm and the transverse REFERENCES diameter about 4.6 mm. Sutures are obscurely recog Adkins, W. S., 1920r The Weno and Pawpaw formations of the nizable on the crushed side of the fragment where the Texas Comanchean: Texas Univ. Bull. 1856. shell has been partly peeled off, and one incomplete ——— 1928, Handbook of Texas Cretaceous fossils: Texas Univ. septum is uncovered at the small broken end of the conch. Bull. 2838. ———1933, The geology of Texas; Pt. 2, The Mesozoic systems U.S.N.M. 108363. in Texas: Texas Univ. Bull. 3232, pp. 239-518. This short, incomplete specimen of Baculites appears ———— and Lozo, F. E., 1951, Stratigraphy of the Woodbine and to be smooth, lacking the oblique cross undulations that Eagle Ford, Waco "area, Texas, in Adkins, W. S., and others, characterize a similar species common in the Metoico- 1951, The Woodbine and adjacent strata of the Waco area ceras whitei zone in the Eagle Ford shale 50 or 60 feet of central Texas: Fondren Science Series 4 (Dallas), pp. 101-164, 6 pis. above its base in Texas. This species from the Eagle Loeblich, A. R., Jr., 1946, Foraminifera from the Pepper stale Ford formation is usually referred to B. gracilis B. F. of Texas: Jour. Paleontology, vol. 20, no. 2, pp. 130-139, Shumard, but is now considered by J. B. Reeside, Jr. pi. 22, 3 figs. 66 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952

Lozo, F. E., 1951, Stratigraphy of the Woodbine and Eagle Ford, Shumard, B. F., 1860, Descriptions of new Cretaceous fossils Waco area, Texas, in Adkins, W. S., and others, 1951, from Texas: Acad. Sci. St. Louis Trans., vol. 1, pjr. 590-610. Stratigraphic notes on the Maness (Comanche Cretaceous) Stephenson, L. W., 1927, Notes on the stratigraphy of the Upper shale: Fondren Science Ser. 4 (Dallas), pp. 65-92, 7 figs. Cretaceous formations of Texas and Arkansas: Am. Assoc. 2 pis. Petroleum Geologists Bull., vol. 11, no. 1, pp. 1-3 7. Plummer, Helen Jeanne, 1933, cited in Adkins, W. S., The geol- ———1953, Larger invertebrate fossils of the Woodbine forma- ogy of Texas; Pt. 2, The Mesozoic systems in Texas: Texas tion (Cenomanian) of Texas: U. S. Geol. Survey Prof. Paper Univ. Bull 3232, pp. 419-420. 242. INDEX

[Italic numbers indicate descriptions] Page Page Acanthoceras______59, 65 Historical sketch- 57 Adkins, W. S., and Lozo, F. E., quoted__——__—__————— 58 Anchura umbrana______59, 6^, pi. IS levis, Sinonia- ___ —————————————————————————————— 63 Anomia ponticulana ______—_—__—_———————— 59, 61 Loeblich, A. R., Jr., quoted ——————————————————————— 58 aquillana, Exogyra_——______— 59, 60, pi. 13 lozoi, Sinonia————— ————————————— + ————— 59, «2,r1. 13 Baculites comanchensis______—_ 65 Metoicoceras _ ———————————————————————————————— 6**' 65 gracilis ______——————————————_————— 59, 65 whitei ______———————————————————————— 65 sp ——————————.—————___—______————— 65 moodiana, Parmicorbula —————————————————————— 59, 63, fl- 13 Breviarca (Sanoarca) calciana______— 59, 60, pi. 13 nodana, Cyclorisma __ ——————————————————————— 59, 61, ^ 13 faucana______,——————————————————— 60 habita______60 orbiculata, Cyclorisma- 62 spiritalis______59, 60, pi. 13 Ostrea soJeniscus 60 sp calciana, Breviarca (Sanoarca) ______59, 60, pi. 13 carolinensis, Cyclorisma______62 Parmicorbula corneliana ————————————————————————— 64 Comanche series______58 hillensis --——-————————————————————————— 63 comancJiensis, Baculites- ______65 moodiana _ ———————————————————————————— 59, 63, r'- 13 Corbula hillensis___———______59, 63, pi. 13 patella, Cyprimeria —— _ —————————————————————————— 59, 61 corneliana, Parmicorbula-______64 Pepper shale, sections ———————————————————————————— 5*M>9 Cyclorisma carolinensis______62 pinguis, Fulpia —————————————————————————— - 59, 61 nodana ______—————______59, 61, pi. 13 ponticulana, Anomia ———————————————————————————— 59, 61 orbiculata______62 Plummer, H. J., quoted —————————————————————————— 57 Cyprimeria patella___—______59, 61 CyrtocMlus ______65 References. 65 Del Rio clay. 58 (Sanoarca) calciana, Breviarca ————————————————— 59, 60, r^- 13 faucana, Breviarca —————————————————————————— 60 Eagle Ford shale______58 habita, Breviarca ———————————————————————————— 60 Exogyra aquillana______59, 60, pi. 13 spiritalis, Breviarca ——————————————————— 59, 60, r1. 13 sp——————————————______60 Sciponoceras __ _ _ — _ —————————————————————————— 65 Sections, Pepper shale ——————————————————————————— 5^—59 faucana, Breviarca (Sanoarca) ______60 shuleri, Turritella ———————————————————————————————— 64 Fulpia—______62 Sinonia levis ————————————————————————————————— 63 pinguis_—___—______59, 61 lozoi ———————— - —— ———————————————— 59, «2, r1. 13 soleniscus, Ostrea —— _ —————— ——————————————————— 60 BacuUtes______59, 65 Grayson marl—————_—_——______58 spiritalis, Breviarca (Sanoarca) ———————— t ————————— 59,60,1^- 13 Gulf series._____—______58 Turritella shuleri ————————————————————————— 64 habita, Breviarca (Sanoarca) ______60 shuleri pepperana— —————————————————— 59, fi^T1 - 13 Haunted Hill, molluscan fossils——__—______—____ 59 umbrana, Anchura ——————————— —————————————— 59, fi^T1- 13 section———————————_————————______58-59 hillensis, Corbula______59, 63, pi. 13 whitei, Metoicoceras — _ ————————————————— ———————— 65 Parmicorbula__—______63 Woodbine formation __ —————————————————————————— 58, 59 67

PLATE 13 PLATE 13 [With the exception of the holotype and one paratype of Exogyra aquillana, n. sp. all the specimens illustrated on this plate are from the Pepper shale at Haunted Hill, McLennan County, Texas, TJ.S.Q.S. coll. 23634] FIGURES 1,2. Breviarca (Sanoarca) spiritalis, n. sp. (p. 59). Side and dorsal views, X 4, of the holotype (a right valve) U.S.N.M. 108336. 3, 4. Breviarca (Sanoarca) caldana, n. sp. (p. 60). 3. Side view, X 4, of the holdtype, (a left valve), U.S.N.M. 108338. 4. Hinge view, X 4, of a paratype, (a left valve), U.S.N.M.108339. The numerous small transverse teeth are only obscurely shown on figure 4. 5—8. Exogyra aquillana, n. sp. (p. 60). 5. 6. Side and front views, X 2, of the holotype, (a left valve), from Aquilla Creek, 1.2 miles east of Aquilla, Hill County, Texas, U.S.N.M. 105225a. (From U.S.G.S. coll. 19018.) 7. Side view, X 2, of a paratype, (a left valve), from the same source, U.S.N.M. 105225b. 8. Side view, X 2, of a paratype, (a left valve), from the Pepper shale at Haunted Hill, U. S.N.M. 108342. 9-12. Cyclorisma nodana, n. sp. (p. 61). 9. 10. Side and hinge views, X 3, of the holotype, (a left valve), U.S.N.M. 108347. 11,12. Hinge views, X 3, of 2 paratypes, (right and left valves), U.S.N.M. 108348. 13-15. Sinonia lozoi, n. sp. (p. 62). 13, 14. Side and hinge views, X 1& of the holotype, (a left valve), U.S.N.M. 108350. 15. Incomplete hinge, X 3, of a paratype, (a right valve), U.S.N.M.108351. 16-20. "Corbula" hillensis Stephenson (p. 63). 16. 17. Side and hinge views, X 2, of a plesiotype, (a right valve), U.S.N.M. 108353a. 18, 19. Side and hinge views, X 2, of a plesiotype, (a left valve), U.S.N.M. 108353b. 20. Side view, X 2, of a plesiotype, (a right valve), U.S.N.M. 108353c. 21—23. Parmicorbula moodiana, n. sp. (p. 63). 21. Side view, X 4, of the holotype, (a right valve), U.S.N.M. 108355. 22. Side view, X 4, of a paratype, (a right valve), U.S.N.M. 108356. 23. Side view, X 4, of a paratype, (a left valve), U.S.N.M. 108356. 24. Turritella shuleri pepperana, new var. (p. 64). The holotype, X 3, U.S.N.M. 108358. 25-30. Anchura umbrana, n. sp. (p. 64). 25, 26. Front and back views, X 2, of the holotype, U.S.N.M. 108360. 27-29. Views, X 2, of 3 paratypes, U.S.N.M. 108361. 30. Interior view, X 2, of an expanded outer lip of a paratype, U.S.N.M. 108361. 31. Baculites sp. (p. 65). A fragment, X 2, showing smooth outer surface, U.S.N.M. 108363.

V. 9. 60VERHHEHT PRIMTINS OFFICEi 1953 PROFESSIONAL PAPER 243 PLATE 13 GEOLOGICAL SURVEY

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MOLLUSCAN FOSSILS MAINLY FROM THE PEPPER SHALE